1. Field of the Invention
The present invention generally relates to chassis-based servers and, more particularly, to providing the flexibility to route data to/from one or more ports to different data paths.
2. Description of the Related Art
Chassis based servers, such as blade servers, generally provide a number of benefits as a result of their physical design and architecture. By sharing resources such as power, cooling, and interconnections through an integrated enclosure or chassis, such systems often eliminate much of the complexity and inefficient overlap of resources of conventional rack-based server systems. For example, by moving power supplies out of individual servers and into the chassis, the number of individual power cables and overall power consumption of the system can be significantly reduced. Chassis-based server systems also take up less area than a comparable rack-based server system, allowing a reduction in necessary floor space.
Further, by providing network connectivity within the chassis, overall cabling cost and complexity may also be significantly reduced. This also simplifies future changes, as the enclosure needs to be wired only once during initial setup and requires little or no additional wiring to accommodate new components. As an example, servers may be added to the system by simply plugging them into available slots and/or old servers may be replaced with new servers, with minimal change in cabling. Chassis-based server systems often provide two or more slots for Ethernet switches, in an effort to provide a redundant network deployment. As is typical in such redundant network deployments, these switches may be connected together. In some cases, these switch interconnections may be efficiently hardwired into the backplane.
FIG. 1A illustrates a chassis-based server system 100 in which a pair of redundant switches 110 (Switch 1 1101 and Switch 2 1102) serve to route network traffic for a plurality of servers 120 connected via a backplane 130. As illustrated, Switch 1 1101 may be connected to a network 150 via an uplink connection to a first network Switch A 160A, while Switch 2 1102 may be connected to the network 150 via an uplink connection to a second network Switch B 160B. To provide redundancy, the switches 110 may be connected to each other via cross-connects 132 hardwired in the backplane 130. By connecting the switches 110 together, the number of uplink cables and dedicated uplink ports from each switch may be reduced. For example, if the uplink for one of the switches 110 fails, the other switch can take over by rerouting traffic from the switch with the failing uplink to the other switch via the cross-connects 132.
While these cross-connects 132 are important to users that implement redundancy in this manner, some users choose a different approach. As a result, in some cases, unused cross-connects 132 may consume otherwise usable Ethernet channels on the switches 110, which is important as there are only a limited number of channels available on each switch. As illustrated in FIG. 1B, for some applications, switch cross-connects may be removed from the backplane 130, thus freeing up Ethernet channels. A user may still have the option of manually connecting Switch 1 and Switch 2 via external cabling 142 or using these ether channels for another purpose. Unfortunately, this approach diminishes one of the typical advantages of chassis-based servers to minimize cable interconnects. Such cables routed across the servers 120 may have to be removed if a server 120, or switch 110, is added or replaced.
Therefore, there is a need for a flexible routing approach that allows a user the option of implementing switch cross-connects in a backplane without dedicating valuable resources (e.g., Ethernet channels).